An important improvement to the design of smaller, high-performance watercraft is the incorporation of a flotation devices in or on the hull that prevents the boat from sinking in virtually any accident scenario, and may additionally add stability to the boat performance during operation. Additionally, flotation devices provide the boat with added buoyancy, thus increasing carrying capacity and safety. The installation of flotation devices is especially important in the case of small boats which are designed for operation on rough waters, such as in the case of rescue boats.
Many prior art boat designs incorporate foam devices within the hull of the boat, as in U.S. Pat. No. 4,060,865 to Woolworth. Typically, the foam flotation members are incorporated directly within the hull structure itself. These boat designs are generally safer than designs which do not incorporate flotation devices within the hull.
Other prior art boat designs use inflatable cylinders to form the sides of the boat, as in the case of Zodiac® boats. The inflatable cylinders provide a high degree of stability to the boat but result in a loss of performance. Generally, prior art inflatable boat designs use inflatable cylinders as the sides of the boat and either a flexible floorboard or a rigid floorboard formed of wood or fiberglass. In operation, the cylinders serve as the running surface for the boat and remain in contact with the surface of the water; thus, a substantial wetted surface area and a significant amount of drag are created. This design also results in a very poor ride due to the fact that the boat tends to skip or bounce over the top of the waves. In addition, the inflatable cylinders are easily damaged and must constantly be inspected for tears, leaks, etc. Another disadvantage to inflatable boats is that typically the interior of the boat is very small, thus leaving little room for carrying equipment or passengers.
Another prior art design is a boat stabilized with outboard foam stabilizing members. Generally, such prior art designs use a rigid, planing hull having a transom and a pair of curved sides extending forwardly from the transom to form the bow of the watercraft. The sides and bottom of the hull are joined to form a chine. Foam stabilizing members are mounted on the sides of the hull above the chine and extend from the transom along the length of the hull to the bow. The stabilizing members extend outwardly from the sides of the hull so that they contact and displace an increasing volume of water as the boat lists. An example of a foam stabilized watercraft design is disclosed in U.S. Pat. No. 5,870,965, which is hereby incorporated by reference in its entirety.
As disclosed below, however, it has been found advantageous to provide a fin on the bottom surface of a forward portion of the stabilizing members to form a channel for providing hydrodynamic lift during certain watercraft operating conditions, as disclosed below.